/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2009 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/

/** @file SDL_video.h
 *  Header file for access to the SDL raw framebuffer window
 */

#ifndef _SDL_video_h
#define _SDL_video_h

#include "SDL_stdinc.h"
#include "SDL_error.h"
#include "SDL_rwops.h"

#include "begin_code.h"
/* Set up for C function definitions, even when using C++ */
#ifdef __cplusplus
extern "C" {
#endif

    /** @name Transparency definitions
     *  These define alpha as the opacity of a surface
     */
    /*@{*/
#define SDL_ALPHA_OPAQUE 255
#define SDL_ALPHA_TRANSPARENT 0
    /*@}*/

    /** @name Useful data types */
    /*@{*/
    typedef struct SDL_Rect {
        Sint16 x, y;
        Uint16 w, h;
    } SDL_Rect;

    typedef struct SDL_Color {
        Uint8 r;
        Uint8 g;
        Uint8 b;
        Uint8 unused;
    } SDL_Color;
#define SDL_Colour SDL_Color

    typedef struct SDL_Palette {
        int       ncolors;
        SDL_Color *colors;
    } SDL_Palette;
    /*@}*/

    /** Everything in the pixel format structure is read-only */
    typedef struct SDL_PixelFormat {
        SDL_Palette *palette;
        Uint8  BitsPerPixel;
        Uint8  BytesPerPixel;
        Uint8  Rloss;
        Uint8  Gloss;
        Uint8  Bloss;
        Uint8  Aloss;
        Uint8  Rshift;
        Uint8  Gshift;
        Uint8  Bshift;
        Uint8  Ashift;
        Uint32 Rmask;
        Uint32 Gmask;
        Uint32 Bmask;
        Uint32 Amask;

        /** RGB color key information */
        Uint32 colorkey;
        /** Alpha value information (per-surface alpha) */
        Uint8  alpha;
    } SDL_PixelFormat;

    /** This structure should be treated as read-only, except for 'pixels',
     *  which, if not NULL, contains the raw pixel data for the surface.
     */
    typedef struct SDL_Surface {
        Uint32 flags;               /**< Read-only */
        SDL_PixelFormat *format;        /**< Read-only */
        int w, h;               /**< Read-only */
        Uint16 pitch;               /**< Read-only */
        void *pixels;               /**< Read-write */
        int offset;             /**< Private */

        /** Hardware-specific surface info */
        struct private_hwdata *hwdata;

        /** clipping information */
        SDL_Rect clip_rect;         /**< Read-only */
        Uint32 unused1;             /**< for binary compatibility */

        /** Allow recursive locks */
        Uint32 locked;              /**< Private */

        /** info for fast blit mapping to other surfaces */
        struct SDL_BlitMap *map;        /**< Private */

        /** format version, bumped at every change to invalidate blit maps */
        unsigned int format_version;        /**< Private */

        /** Reference count -- used when freeing surface */
        int refcount;               /**< Read-mostly */
    } SDL_Surface;

    /** @name SDL_Surface Flags
     *  These are the currently supported flags for the SDL_surface
     */
    /*@{*/

    /** Available for SDL_CreateRGBSurface() or SDL_SetVideoMode() */
    /*@{*/
#define SDL_SWSURFACE   0x00000000  /**< Surface is in system memory */
#define SDL_HWSURFACE   0x00000001  /**< Surface is in video memory */
#define SDL_ASYNCBLIT   0x00000004  /**< Use asynchronous blits if possible */
    /*@}*/

    /** Available for SDL_SetVideoMode() */
    /*@{*/
#define SDL_ANYFORMAT   0x10000000  /**< Allow any video depth/pixel-format */
#define SDL_HWPALETTE   0x20000000  /**< Surface has exclusive palette */
#define SDL_DOUBLEBUF   0x40000000  /**< Set up double-buffered video mode */
#define SDL_FULLSCREEN  0x80000000  /**< Surface is a full screen display */
#define SDL_OPENGL      0x00000002      /**< Create an OpenGL rendering context */
#define SDL_OPENGLBLIT  0x0000000A  /**< Create an OpenGL rendering context and use it for blitting */
#define SDL_RESIZABLE   0x00000010  /**< This video mode may be resized */
#define SDL_NOFRAME 0x00000020  /**< No window caption or edge frame */
    /*@}*/

    /** Used internally (read-only) */
    /*@{*/
#define SDL_HWACCEL 0x00000100  /**< Blit uses hardware acceleration */
#define SDL_SRCCOLORKEY 0x00001000  /**< Blit uses a source color key */
#define SDL_RLEACCELOK  0x00002000  /**< Private flag */
#define SDL_RLEACCEL    0x00004000  /**< Surface is RLE encoded */
#define SDL_SRCALPHA    0x00010000  /**< Blit uses source alpha blending */
#define SDL_PREALLOC    0x01000000  /**< Surface uses preallocated memory */
    /*@}*/

    /*@}*/

    /** Evaluates to true if the surface needs to be locked before access */
#define SDL_MUSTLOCK(surface)   \
    (surface->offset ||       \
     ((surface->flags & (SDL_HWSURFACE|SDL_ASYNCBLIT|SDL_RLEACCEL)) != 0))

    /** typedef for private surface blitting functions */
    typedef int (*SDL_blit)(struct SDL_Surface *src, SDL_Rect *srcrect,
                            struct SDL_Surface *dst, SDL_Rect *dstrect);


    /** Useful for determining the video hardware capabilities */
    typedef struct SDL_VideoInfo {
        Uint32 hw_available :1; /**< Flag: Can you create hardware surfaces? */
        Uint32 wm_available :1; /**< Flag: Can you talk to a window manager? */
        Uint32 UnusedBits1  :6;
        Uint32 UnusedBits2  :1;
        Uint32 blit_hw      :1; /**< Flag: Accelerated blits HW --> HW */
        Uint32 blit_hw_CC   :1; /**< Flag: Accelerated blits with Colorkey */
        Uint32 blit_hw_A    :1; /**< Flag: Accelerated blits with Alpha */
        Uint32 blit_sw      :1; /**< Flag: Accelerated blits SW --> HW */
        Uint32 blit_sw_CC   :1; /**< Flag: Accelerated blits with Colorkey */
        Uint32 blit_sw_A    :1; /**< Flag: Accelerated blits with Alpha */
        Uint32 blit_fill    :1; /**< Flag: Accelerated color fill */
        Uint32 UnusedBits3  :16;
        Uint32 video_mem;   /**< The total amount of video memory (in K) */
        SDL_PixelFormat *vfmt;  /**< Value: The format of the video surface */
        int    current_w;   /**< Value: The current video mode width */
        int    current_h;   /**< Value: The current video mode height */
    } SDL_VideoInfo;


    /** @name Overlay Formats
     *  The most common video overlay formats.
     *  For an explanation of these pixel formats, see:
     *  http://www.webartz.com/fourcc/indexyuv.htm
     *
     *  For information on the relationship between color spaces, see:
     *  http://www.neuro.sfc.keio.ac.jp/~aly/polygon/info/color-space-faq.html
     */
    /*@{*/
#define SDL_YV12_OVERLAY  0x32315659    /**< Planar mode: Y + V + U  (3 planes) */
#define SDL_IYUV_OVERLAY  0x56555949    /**< Planar mode: Y + U + V  (3 planes) */
#define SDL_YUY2_OVERLAY  0x32595559    /**< Packed mode: Y0+U0+Y1+V0 (1 plane) */
#define SDL_UYVY_OVERLAY  0x59565955    /**< Packed mode: U0+Y0+V0+Y1 (1 plane) */
#define SDL_YVYU_OVERLAY  0x55595659    /**< Packed mode: Y0+V0+Y1+U0 (1 plane) */
    /*@}*/

    /** The YUV hardware video overlay */
    typedef struct SDL_Overlay {
        Uint32 format;              /**< Read-only */
        int w, h;               /**< Read-only */
        int planes;             /**< Read-only */
        Uint16 *pitches;            /**< Read-only */
        Uint8 **pixels;             /**< Read-write */

        /** @name Hardware-specific surface info */
        /*@{*/
        struct private_yuvhwfuncs *hwfuncs;
        struct private_yuvhwdata *hwdata;
        /*@{*/

        /** @name Special flags */
        /*@{*/
        Uint32 hw_overlay :1;   /**< Flag: This overlay hardware accelerated? */
        Uint32 UnusedBits :31;
        /*@}*/
    } SDL_Overlay;


    /** Public enumeration for setting the OpenGL window attributes. */
    typedef enum {
        SDL_GL_RED_SIZE,
        SDL_GL_GREEN_SIZE,
        SDL_GL_BLUE_SIZE,
        SDL_GL_ALPHA_SIZE,
        SDL_GL_BUFFER_SIZE,
        SDL_GL_DOUBLEBUFFER,
        SDL_GL_DEPTH_SIZE,
        SDL_GL_STENCIL_SIZE,
        SDL_GL_ACCUM_RED_SIZE,
        SDL_GL_ACCUM_GREEN_SIZE,
        SDL_GL_ACCUM_BLUE_SIZE,
        SDL_GL_ACCUM_ALPHA_SIZE,
        SDL_GL_STEREO,
        SDL_GL_MULTISAMPLEBUFFERS,
        SDL_GL_MULTISAMPLESAMPLES,
        SDL_GL_ACCELERATED_VISUAL,
        SDL_GL_SWAP_CONTROL
    } SDL_GLattr;

    /** @name flags for SDL_SetPalette() */
    /*@{*/
#define SDL_LOGPAL 0x01
#define SDL_PHYSPAL 0x02
    /*@}*/

    /* Function prototypes */

    /**
     * @name Video Init and Quit
     * These functions are used internally, and should not be used unless you
     * have a specific need to specify the video driver you want to use.
     * You should normally use SDL_Init() or SDL_InitSubSystem().
     */
    /*@{*/
    /**
     * Initializes the video subsystem. Sets up a connection
     * to the window manager, etc, and determines the current video mode and
     * pixel format, but does not initialize a window or graphics mode.
     * Note that event handling is activated by this routine.
     *
     * If you use both sound and video in your application, you need to call
     * SDL_Init() before opening the sound device, otherwise under Win32 DirectX,
     * you won't be able to set full-screen display modes.
     */
    extern DECLSPEC int SDLCALL SDL_VideoInit(const char *driver_name, Uint32 flags);
    extern DECLSPEC void SDLCALL SDL_VideoQuit(void);
    /*@}*/

    /**
     * This function fills the given character buffer with the name of the
     * video driver, and returns a pointer to it if the video driver has
     * been initialized.  It returns NULL if no driver has been initialized.
     */
    extern DECLSPEC char *SDLCALL SDL_VideoDriverName(char *namebuf, int maxlen);

    /**
     * This function returns a pointer to the current display surface.
     * If SDL is doing format conversion on the display surface, this
     * function returns the publicly visible surface, not the real video
     * surface.
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_GetVideoSurface(void);

    /**
     * This function returns a read-only pointer to information about the
     * video hardware.  If this is called before SDL_SetVideoMode(), the 'vfmt'
     * member of the returned structure will contain the pixel format of the
     * "best" video mode.
     */
    extern DECLSPEC const SDL_VideoInfo *SDLCALL SDL_GetVideoInfo(void);

    /**
     * Check to see if a particular video mode is supported.
     * It returns 0 if the requested mode is not supported under any bit depth,
     * or returns the bits-per-pixel of the closest available mode with the
     * given width and height.  If this bits-per-pixel is different from the
     * one used when setting the video mode, SDL_SetVideoMode() will succeed,
     * but will emulate the requested bits-per-pixel with a shadow surface.
     *
     * The arguments to SDL_VideoModeOK() are the same ones you would pass to
     * SDL_SetVideoMode()
     */
    extern DECLSPEC int SDLCALL SDL_VideoModeOK(int width, int height, int bpp, Uint32 flags);

    /**
     * Return a pointer to an array of available screen dimensions for the
     * given format and video flags, sorted largest to smallest.  Returns
     * NULL if there are no dimensions available for a particular format,
     * or (SDL_Rect **)-1 if any dimension is okay for the given format.
     *
     * If 'format' is NULL, the mode list will be for the format given
     * by SDL_GetVideoInfo()->vfmt
     */
    extern DECLSPEC SDL_Rect **SDLCALL SDL_ListModes(SDL_PixelFormat *format, Uint32 flags);

    /**
     * Set up a video mode with the specified width, height and bits-per-pixel.
     *
     * If 'bpp' is 0, it is treated as the current display bits per pixel.
     *
     * If SDL_ANYFORMAT is set in 'flags', the SDL library will try to set the
     * requested bits-per-pixel, but will return whatever video pixel format is
     * available.  The default is to emulate the requested pixel format if it
     * is not natively available.
     *
     * If SDL_HWSURFACE is set in 'flags', the video surface will be placed in
     * video memory, if possible, and you may have to call SDL_LockSurface()
     * in order to access the raw framebuffer.  Otherwise, the video surface
     * will be created in system memory.
     *
     * If SDL_ASYNCBLIT is set in 'flags', SDL will try to perform rectangle
     * updates asynchronously, but you must always lock before accessing pixels.
     * SDL will wait for updates to complete before returning from the lock.
     *
     * If SDL_HWPALETTE is set in 'flags', the SDL library will guarantee
     * that the colors set by SDL_SetColors() will be the colors you get.
     * Otherwise, in 8-bit mode, SDL_SetColors() may not be able to set all
     * of the colors exactly the way they are requested, and you should look
     * at the video surface structure to determine the actual palette.
     * If SDL cannot guarantee that the colors you request can be set,
     * i.e. if the colormap is shared, then the video surface may be created
     * under emulation in system memory, overriding the SDL_HWSURFACE flag.
     *
     * If SDL_FULLSCREEN is set in 'flags', the SDL library will try to set
     * a fullscreen video mode.  The default is to create a windowed mode
     * if the current graphics system has a window manager.
     * If the SDL library is able to set a fullscreen video mode, this flag
     * will be set in the surface that is returned.
     *
     * If SDL_DOUBLEBUF is set in 'flags', the SDL library will try to set up
     * two surfaces in video memory and swap between them when you call
     * SDL_Flip().  This is usually slower than the normal single-buffering
     * scheme, but prevents "tearing" artifacts caused by modifying video
     * memory while the monitor is refreshing.  It should only be used by
     * applications that redraw the entire screen on every update.
     *
     * If SDL_RESIZABLE is set in 'flags', the SDL library will allow the
     * window manager, if any, to resize the window at runtime.  When this
     * occurs, SDL will send a SDL_VIDEORESIZE event to you application,
     * and you must respond to the event by re-calling SDL_SetVideoMode()
     * with the requested size (or another size that suits the application).
     *
     * If SDL_NOFRAME is set in 'flags', the SDL library will create a window
     * without any title bar or frame decoration.  Fullscreen video modes have
     * this flag set automatically.
     *
     * This function returns the video framebuffer surface, or NULL if it fails.
     *
     * If you rely on functionality provided by certain video flags, check the
     * flags of the returned surface to make sure that functionality is available.
     * SDL will fall back to reduced functionality if the exact flags you wanted
     * are not available.
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_SetVideoMode
    (int width, int height, int bpp, Uint32 flags);

    /** @name SDL_Update Functions
     * These functions should not be called while 'screen' is locked.
     */
    /*@{*/
    /**
     * Makes sure the given list of rectangles is updated on the given screen.
     */
    extern DECLSPEC void SDLCALL SDL_UpdateRects
    (SDL_Surface *screen, int numrects, SDL_Rect *rects);
    /**
     * If 'x', 'y', 'w' and 'h' are all 0, SDL_UpdateRect will update the entire
     * screen.
     */
    extern DECLSPEC void SDLCALL SDL_UpdateRect
    (SDL_Surface *screen, Sint32 x, Sint32 y, Uint32 w, Uint32 h);
    /*@}*/

    /**
     * On hardware that supports double-buffering, this function sets up a flip
     * and returns.  The hardware will wait for vertical retrace, and then swap
     * video buffers before the next video surface blit or lock will return.
     * On hardware that doesn not support double-buffering, this is equivalent
     * to calling SDL_UpdateRect(screen, 0, 0, 0, 0);
     * The SDL_DOUBLEBUF flag must have been passed to SDL_SetVideoMode() when
     * setting the video mode for this function to perform hardware flipping.
     * This function returns 0 if successful, or -1 if there was an error.
     */
    extern DECLSPEC int SDLCALL SDL_Flip(SDL_Surface *screen);

    /**
     * Set the gamma correction for each of the color channels.
     * The gamma values range (approximately) between 0.1 and 10.0
     *
     * If this function isn't supported directly by the hardware, it will
     * be emulated using gamma ramps, if available.  If successful, this
     * function returns 0, otherwise it returns -1.
     */
    extern DECLSPEC int SDLCALL SDL_SetGamma(float red, float green, float blue);

    /**
     * Set the gamma translation table for the red, green, and blue channels
     * of the video hardware.  Each table is an array of 256 16-bit quantities,
     * representing a mapping between the input and output for that channel.
     * The input is the index into the array, and the output is the 16-bit
     * gamma value at that index, scaled to the output color precision.
     *
     * You may pass NULL for any of the channels to leave it unchanged.
     * If the call succeeds, it will return 0.  If the display driver or
     * hardware does not support gamma translation, or otherwise fails,
     * this function will return -1.
     */
    extern DECLSPEC int SDLCALL SDL_SetGammaRamp(const Uint16 *red, const Uint16 *green, const Uint16 *blue);

    /**
     * Retrieve the current values of the gamma translation tables.
     *
     * You must pass in valid pointers to arrays of 256 16-bit quantities.
     * Any of the pointers may be NULL to ignore that channel.
     * If the call succeeds, it will return 0.  If the display driver or
     * hardware does not support gamma translation, or otherwise fails,
     * this function will return -1.
     */
    extern DECLSPEC int SDLCALL SDL_GetGammaRamp(Uint16 *red, Uint16 *green, Uint16 *blue);

    /**
     * Sets a portion of the colormap for the given 8-bit surface.  If 'surface'
     * is not a palettized surface, this function does nothing, returning 0.
     * If all of the colors were set as passed to SDL_SetColors(), it will
     * return 1.  If not all the color entries were set exactly as given,
     * it will return 0, and you should look at the surface palette to
     * determine the actual color palette.
     *
     * When 'surface' is the surface associated with the current display, the
     * display colormap will be updated with the requested colors.  If
     * SDL_HWPALETTE was set in SDL_SetVideoMode() flags, SDL_SetColors()
     * will always return 1, and the palette is guaranteed to be set the way
     * you desire, even if the window colormap has to be warped or run under
     * emulation.
     */
    extern DECLSPEC int SDLCALL SDL_SetColors(SDL_Surface *surface,
                                              SDL_Color *colors, int firstcolor, int ncolors);

    /**
     * Sets a portion of the colormap for a given 8-bit surface.
     * 'flags' is one or both of:
     * SDL_LOGPAL  -- set logical palette, which controls how blits are mapped
     *                to/from the surface,
     * SDL_PHYSPAL -- set physical palette, which controls how pixels look on
     *                the screen
     * Only screens have physical palettes. Separate change of physical/logical
     * palettes is only possible if the screen has SDL_HWPALETTE set.
     *
     * The return value is 1 if all colours could be set as requested, and 0
     * otherwise.
     *
     * SDL_SetColors() is equivalent to calling this function with
     *     flags = (SDL_LOGPAL|SDL_PHYSPAL).
     */
    extern DECLSPEC int SDLCALL SDL_SetPalette(SDL_Surface *surface, int flags,
                                               SDL_Color *colors, int firstcolor,
                                               int ncolors);

    /**
     * Maps an RGB triple to an opaque pixel value for a given pixel format
     */
    extern DECLSPEC Uint32 SDLCALL SDL_MapRGB
    (const SDL_PixelFormat *const format,
     const Uint8 r, const Uint8 g, const Uint8 b);

    /**
     * Maps an RGBA quadruple to a pixel value for a given pixel format
     */
    extern DECLSPEC Uint32 SDLCALL SDL_MapRGBA
    (const SDL_PixelFormat *const format,
     const Uint8 r, const Uint8 g, const Uint8 b, const Uint8 a);

    /**
     * Maps a pixel value into the RGB components for a given pixel format
     */
    extern DECLSPEC void SDLCALL SDL_GetRGB(Uint32 pixel,
                                            const SDL_PixelFormat *const fmt,
                                            Uint8 *r, Uint8 *g, Uint8 *b);

    /**
     * Maps a pixel value into the RGBA components for a given pixel format
     */
    extern DECLSPEC void SDLCALL SDL_GetRGBA(Uint32 pixel,
                                             const SDL_PixelFormat *const fmt,
                                             Uint8 *r, Uint8 *g, Uint8 *b, Uint8 *a);

    /** @sa SDL_CreateRGBSurface */
#define SDL_AllocSurface    SDL_CreateRGBSurface
    /**
     * Allocate and free an RGB surface (must be called after SDL_SetVideoMode)
     * If the depth is 4 or 8 bits, an empty palette is allocated for the surface.
     * If the depth is greater than 8 bits, the pixel format is set using the
     * flags '[RGB]mask'.
     * If the function runs out of memory, it will return NULL.
     *
     * The 'flags' tell what kind of surface to create.
     * SDL_SWSURFACE means that the surface should be created in system memory.
     * SDL_HWSURFACE means that the surface should be created in video memory,
     * with the same format as the display surface.  This is useful for surfaces
     * that will not change much, to take advantage of hardware acceleration
     * when being blitted to the display surface.
     * SDL_ASYNCBLIT means that SDL will try to perform asynchronous blits with
     * this surface, but you must always lock it before accessing the pixels.
     * SDL will wait for current blits to finish before returning from the lock.
     * SDL_SRCCOLORKEY indicates that the surface will be used for colorkey blits.
     * If the hardware supports acceleration of colorkey blits between
     * two surfaces in video memory, SDL will try to place the surface in
     * video memory. If this isn't possible or if there is no hardware
     * acceleration available, the surface will be placed in system memory.
     * SDL_SRCALPHA means that the surface will be used for alpha blits and
     * if the hardware supports hardware acceleration of alpha blits between
     * two surfaces in video memory, to place the surface in video memory
     * if possible, otherwise it will be placed in system memory.
     * If the surface is created in video memory, blits will be _much_ faster,
     * but the surface format must be identical to the video surface format,
     * and the only way to access the pixels member of the surface is to use
     * the SDL_LockSurface() and SDL_UnlockSurface() calls.
     * If the requested surface actually resides in video memory, SDL_HWSURFACE
     * will be set in the flags member of the returned surface.  If for some
     * reason the surface could not be placed in video memory, it will not have
     * the SDL_HWSURFACE flag set, and will be created in system memory instead.
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_CreateRGBSurface
    (Uint32 flags, int width, int height, int depth,
     Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
    /** @sa SDL_CreateRGBSurface */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_CreateRGBSurfaceFrom(void *pixels,
            int width, int height, int depth, int pitch,
            Uint32 Rmask, Uint32 Gmask, Uint32 Bmask, Uint32 Amask);
    extern DECLSPEC void SDLCALL SDL_FreeSurface(SDL_Surface *surface);

    /**
     * SDL_LockSurface() sets up a surface for directly accessing the pixels.
     * Between calls to SDL_LockSurface()/SDL_UnlockSurface(), you can write
     * to and read from 'surface->pixels', using the pixel format stored in
     * 'surface->format'.  Once you are done accessing the surface, you should
     * use SDL_UnlockSurface() to release it.
     *
     * Not all surfaces require locking.  If SDL_MUSTLOCK(surface) evaluates
     * to 0, then you can read and write to the surface at any time, and the
     * pixel format of the surface will not change.  In particular, if the
     * SDL_HWSURFACE flag is not given when calling SDL_SetVideoMode(), you
     * will not need to lock the display surface before accessing it.
     *
     * No operating system or library calls should be made between lock/unlock
     * pairs, as critical system locks may be held during this time.
     *
     * SDL_LockSurface() returns 0, or -1 if the surface couldn't be locked.
     */
    extern DECLSPEC int SDLCALL SDL_LockSurface(SDL_Surface *surface);
    extern DECLSPEC void SDLCALL SDL_UnlockSurface(SDL_Surface *surface);

    /**
     * Load a surface from a seekable SDL data source (memory or file.)
     * If 'freesrc' is non-zero, the source will be closed after being read.
     * Returns the new surface, or NULL if there was an error.
     * The new surface should be freed with SDL_FreeSurface().
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_LoadBMP_RW(SDL_RWops *src, int freesrc);

    /** Convenience macro -- load a surface from a file */
#define SDL_LoadBMP(file)   SDL_LoadBMP_RW(SDL_RWFromFile(file, "rb"), 1)

    /**
     * Save a surface to a seekable SDL data source (memory or file.)
     * If 'freedst' is non-zero, the source will be closed after being written.
     * Returns 0 if successful or -1 if there was an error.
     */
    extern DECLSPEC int SDLCALL SDL_SaveBMP_RW
    (SDL_Surface *surface, SDL_RWops *dst, int freedst);

    /** Convenience macro -- save a surface to a file */
#define SDL_SaveBMP(surface, file) \
    SDL_SaveBMP_RW(surface, SDL_RWFromFile(file, "wb"), 1)

    /**
     * Sets the color key (transparent pixel) in a blittable surface.
     * If 'flag' is SDL_SRCCOLORKEY (optionally OR'd with SDL_RLEACCEL),
     * 'key' will be the transparent pixel in the source image of a blit.
     * SDL_RLEACCEL requests RLE acceleration for the surface if present,
     * and removes RLE acceleration if absent.
     * If 'flag' is 0, this function clears any current color key.
     * This function returns 0, or -1 if there was an error.
     */
    extern DECLSPEC int SDLCALL SDL_SetColorKey
    (SDL_Surface *surface, Uint32 flag, Uint32 key);

    /**
     * This function sets the alpha value for the entire surface, as opposed to
     * using the alpha component of each pixel. This value measures the range
     * of transparency of the surface, 0 being completely transparent to 255
     * being completely opaque. An 'alpha' value of 255 causes blits to be
     * opaque, the source pixels copied to the destination (the default). Note
     * that per-surface alpha can be combined with colorkey transparency.
     *
     * If 'flag' is 0, alpha blending is disabled for the surface.
     * If 'flag' is SDL_SRCALPHA, alpha blending is enabled for the surface.
     * OR:ing the flag with SDL_RLEACCEL requests RLE acceleration for the
     * surface; if SDL_RLEACCEL is not specified, the RLE accel will be removed.
     *
     * The 'alpha' parameter is ignored for surfaces that have an alpha channel.
     */
    extern DECLSPEC int SDLCALL SDL_SetAlpha(SDL_Surface *surface, Uint32 flag, Uint8 alpha);

    /**
     * Sets the clipping rectangle for the destination surface in a blit.
     *
     * If the clip rectangle is NULL, clipping will be disabled.
     * If the clip rectangle doesn't intersect the surface, the function will
     * return SDL_FALSE and blits will be completely clipped.  Otherwise the
     * function returns SDL_TRUE and blits to the surface will be clipped to
     * the intersection of the surface area and the clipping rectangle.
     *
     * Note that blits are automatically clipped to the edges of the source
     * and destination surfaces.
     */
    extern DECLSPEC SDL_bool SDLCALL SDL_SetClipRect(SDL_Surface *surface, const SDL_Rect *rect);

    /**
     * Gets the clipping rectangle for the destination surface in a blit.
     * 'rect' must be a pointer to a valid rectangle which will be filled
     * with the correct values.
     */
    extern DECLSPEC void SDLCALL SDL_GetClipRect(SDL_Surface *surface, SDL_Rect *rect);

    /**
     * Creates a new surface of the specified format, and then copies and maps
     * the given surface to it so the blit of the converted surface will be as
     * fast as possible.  If this function fails, it returns NULL.
     *
     * The 'flags' parameter is passed to SDL_CreateRGBSurface() and has those
     * semantics.  You can also pass SDL_RLEACCEL in the flags parameter and
     * SDL will try to RLE accelerate colorkey and alpha blits in the resulting
     * surface.
     *
     * This function is used internally by SDL_DisplayFormat().
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_ConvertSurface
    (SDL_Surface *src, SDL_PixelFormat *fmt, Uint32 flags);

    /**
     * This performs a fast blit from the source surface to the destination
     * surface.  It assumes that the source and destination rectangles are
     * the same size.  If either 'srcrect' or 'dstrect' are NULL, the entire
     * surface (src or dst) is copied.  The final blit rectangles are saved
     * in 'srcrect' and 'dstrect' after all clipping is performed.
     * If the blit is successful, it returns 0, otherwise it returns -1.
     *
     * The blit function should not be called on a locked surface.
     *
     * The blit semantics for surfaces with and without alpha and colorkey
     * are defined as follows:
     *
     * RGBA->RGB:
     *     SDL_SRCALPHA set:
     *  alpha-blend (using alpha-channel).
     *  SDL_SRCCOLORKEY ignored.
     *     SDL_SRCALPHA not set:
     *  copy RGB.
     *  if SDL_SRCCOLORKEY set, only copy the pixels matching the
     *  RGB values of the source colour key, ignoring alpha in the
     *  comparison.
     *
     * RGB->RGBA:
     *     SDL_SRCALPHA set:
     *  alpha-blend (using the source per-surface alpha value);
     *  set destination alpha to opaque.
     *     SDL_SRCALPHA not set:
     *  copy RGB, set destination alpha to source per-surface alpha value.
     *     both:
     *  if SDL_SRCCOLORKEY set, only copy the pixels matching the
     *  source colour key.
     *
     * RGBA->RGBA:
     *     SDL_SRCALPHA set:
     *  alpha-blend (using the source alpha channel) the RGB values;
     *  leave destination alpha untouched. [Note: is this correct?]
     *  SDL_SRCCOLORKEY ignored.
     *     SDL_SRCALPHA not set:
     *  copy all of RGBA to the destination.
     *  if SDL_SRCCOLORKEY set, only copy the pixels matching the
     *  RGB values of the source colour key, ignoring alpha in the
     *  comparison.
     *
     * RGB->RGB:
     *     SDL_SRCALPHA set:
     *  alpha-blend (using the source per-surface alpha value).
     *     SDL_SRCALPHA not set:
     *  copy RGB.
     *     both:
     *  if SDL_SRCCOLORKEY set, only copy the pixels matching the
     *  source colour key.
     *
     * If either of the surfaces were in video memory, and the blit returns -2,
     * the video memory was lost, so it should be reloaded with artwork and
     * re-blitted:
     * @code
     *  while ( SDL_BlitSurface(image, imgrect, screen, dstrect) == -2 ) {
     *      while ( SDL_LockSurface(image) < 0 )
     *          Sleep(10);
     *      -- Write image pixels to image->pixels --
     *      SDL_UnlockSurface(image);
     *  }
     * @endcode
     *
     * This happens under DirectX 5.0 when the system switches away from your
     * fullscreen application.  The lock will also fail until you have access
     * to the video memory again.
     *
     * You should call SDL_BlitSurface() unless you know exactly how SDL
     * blitting works internally and how to use the other blit functions.
     */
#define SDL_BlitSurface SDL_UpperBlit

    /** This is the public blit function, SDL_BlitSurface(), and it performs
     *  rectangle validation and clipping before passing it to SDL_LowerBlit()
     */
    extern DECLSPEC int SDLCALL SDL_UpperBlit
    (SDL_Surface *src, SDL_Rect *srcrect,
     SDL_Surface *dst, SDL_Rect *dstrect);
    /** This is a semi-private blit function and it performs low-level surface
     *  blitting only.
     */
    extern DECLSPEC int SDLCALL SDL_LowerBlit
    (SDL_Surface *src, SDL_Rect *srcrect,
     SDL_Surface *dst, SDL_Rect *dstrect);

    /**
     * This function performs a fast fill of the given rectangle with 'color'
     * The given rectangle is clipped to the destination surface clip area
     * and the final fill rectangle is saved in the passed in pointer.
     * If 'dstrect' is NULL, the whole surface will be filled with 'color'
     * The color should be a pixel of the format used by the surface, and
     * can be generated by the SDL_MapRGB() function.
     * This function returns 0 on success, or -1 on error.
     */
    extern DECLSPEC int SDLCALL SDL_FillRect
    (SDL_Surface *dst, SDL_Rect *dstrect, Uint32 color);

    /**
     * This function takes a surface and copies it to a new surface of the
     * pixel format and colors of the video framebuffer, suitable for fast
     * blitting onto the display surface.  It calls SDL_ConvertSurface()
     *
     * If you want to take advantage of hardware colorkey or alpha blit
     * acceleration, you should set the colorkey and alpha value before
     * calling this function.
     *
     * If the conversion fails or runs out of memory, it returns NULL
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_DisplayFormat(SDL_Surface *surface);

    /**
     * This function takes a surface and copies it to a new surface of the
     * pixel format and colors of the video framebuffer (if possible),
     * suitable for fast alpha blitting onto the display surface.
     * The new surface will always have an alpha channel.
     *
     * If you want to take advantage of hardware colorkey or alpha blit
     * acceleration, you should set the colorkey and alpha value before
     * calling this function.
     *
     * If the conversion fails or runs out of memory, it returns NULL
     */
    extern DECLSPEC SDL_Surface *SDLCALL SDL_DisplayFormatAlpha(SDL_Surface *surface);


    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /** @name YUV video surface overlay functions                                */ /*@{*/
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

    /** This function creates a video output overlay
     *  Calling the returned surface an overlay is something of a misnomer because
     *  the contents of the display surface underneath the area where the overlay
     *  is shown is undefined - it may be overwritten with the converted YUV data.
     */
    extern DECLSPEC SDL_Overlay *SDLCALL SDL_CreateYUVOverlay(int width, int height,
                                                              Uint32 format, SDL_Surface *display);

    /** Lock an overlay for direct access, and unlock it when you are done */
    extern DECLSPEC int SDLCALL SDL_LockYUVOverlay(SDL_Overlay *overlay);
    extern DECLSPEC void SDLCALL SDL_UnlockYUVOverlay(SDL_Overlay *overlay);

    /** Blit a video overlay to the display surface.
     *  The contents of the video surface underneath the blit destination are
     *  not defined.
     *  The width and height of the destination rectangle may be different from
     *  that of the overlay, but currently only 2x scaling is supported.
     */
    extern DECLSPEC int SDLCALL SDL_DisplayYUVOverlay(SDL_Overlay *overlay, SDL_Rect *dstrect);

    /** Free a video overlay */
    extern DECLSPEC void SDLCALL SDL_FreeYUVOverlay(SDL_Overlay *overlay);

    /*@}*/

    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /** @name OpenGL support functions.                                          */ /*@{*/
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

    /**
     * Dynamically load an OpenGL library, or the default one if path is NULL
     *
     * If you do this, you need to retrieve all of the GL functions used in
     * your program from the dynamic library using SDL_GL_GetProcAddress().
     */
    extern DECLSPEC int SDLCALL SDL_GL_LoadLibrary(const char *path);

    /**
     * Get the address of a GL function
     */
    extern DECLSPEC void *SDLCALL SDL_GL_GetProcAddress(const char *proc);

    /**
     * Set an attribute of the OpenGL subsystem before intialization.
     */
    extern DECLSPEC int SDLCALL SDL_GL_SetAttribute(SDL_GLattr attr, int value);

    /**
     * Get an attribute of the OpenGL subsystem from the windowing
     * interface, such as glX. This is of course different from getting
     * the values from SDL's internal OpenGL subsystem, which only
     * stores the values you request before initialization.
     *
     * Developers should track the values they pass into SDL_GL_SetAttribute
     * themselves if they want to retrieve these values.
     */
    extern DECLSPEC int SDLCALL SDL_GL_GetAttribute(SDL_GLattr attr, int *value);

    /**
     * Swap the OpenGL buffers, if double-buffering is supported.
     */
    extern DECLSPEC void SDLCALL SDL_GL_SwapBuffers(void);

    /** @name OpenGL Internal Functions
     * Internal functions that should not be called unless you have read
     * and understood the source code for these functions.
     */
    /*@{*/
    extern DECLSPEC void SDLCALL SDL_GL_UpdateRects(int numrects, SDL_Rect *rects);
    extern DECLSPEC void SDLCALL SDL_GL_Lock(void);
    extern DECLSPEC void SDLCALL SDL_GL_Unlock(void);
    /*@}*/

    /*@}*/

    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
    /** @name Window Manager Functions                                           */
    /** These functions allow interaction with the window manager, if any.       */ /*@{*/
    /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

    /**
     * Sets the title and icon text of the display window (UTF-8 encoded)
     */
    extern DECLSPEC void SDLCALL SDL_WM_SetCaption(const char *title, const char *icon);
    /**
     * Gets the title and icon text of the display window (UTF-8 encoded)
     */
    extern DECLSPEC void SDLCALL SDL_WM_GetCaption(char **title, char **icon);

    /**
     * Sets the icon for the display window.
     * This function must be called before the first call to SDL_SetVideoMode().
     * It takes an icon surface, and a mask in MSB format.
     * If 'mask' is NULL, the entire icon surface will be used as the icon.
     */
    extern DECLSPEC void SDLCALL SDL_WM_SetIcon(SDL_Surface *icon, Uint8 *mask);

    /**
     * This function iconifies the window, and returns 1 if it succeeded.
     * If the function succeeds, it generates an SDL_APPACTIVE loss event.
     * This function is a noop and returns 0 in non-windowed environments.
     */
    extern DECLSPEC int SDLCALL SDL_WM_IconifyWindow(void);

    /**
     * Toggle fullscreen mode without changing the contents of the screen.
     * If the display surface does not require locking before accessing
     * the pixel information, then the memory pointers will not change.
     *
     * If this function was able to toggle fullscreen mode (change from
     * running in a window to fullscreen, or vice-versa), it will return 1.
     * If it is not implemented, or fails, it returns 0.
     *
     * The next call to SDL_SetVideoMode() will set the mode fullscreen
     * attribute based on the flags parameter - if SDL_FULLSCREEN is not
     * set, then the display will be windowed by default where supported.
     *
     * This is currently only implemented in the X11 video driver.
     */
    extern DECLSPEC int SDLCALL SDL_WM_ToggleFullScreen(SDL_Surface *surface);

    typedef enum {
        SDL_GRAB_QUERY = -1,
        SDL_GRAB_OFF = 0,
        SDL_GRAB_ON = 1,
        SDL_GRAB_FULLSCREEN /**< Used internally */
    } SDL_GrabMode;
    /**
     * This function allows you to set and query the input grab state of
     * the application.  It returns the new input grab state.
     *
     * Grabbing means that the mouse is confined to the application window,
     * and nearly all keyboard input is passed directly to the application,
     * and not interpreted by a window manager, if any.
     */
    extern DECLSPEC SDL_GrabMode SDLCALL SDL_WM_GrabInput(SDL_GrabMode mode);

    /*@}*/

    /** @internal Not in public API at the moment - do not use! */
    extern DECLSPEC int SDLCALL SDL_SoftStretch(SDL_Surface *src, SDL_Rect *srcrect,
                                                SDL_Surface *dst, SDL_Rect *dstrect);

    /* Ends C function definitions when using C++ */
#ifdef __cplusplus
}
#endif
#include "close_code.h"

#endif /* _SDL_video_h */
